Schwartz’s catfish Care Guide: Diet, Tank Mates, Diseases, Breeding & More

Updated: October 23, 2022

Schwartz’s catfish (Heteropneustes schwanenfeldii) is a beautiful and unique freshwater fish that is native to Southeast Asia. It is named after German zoologist and explorer, Otto Schwartz, who first described the species in 1866.

This fish is not commonly found in the aquarium trade, but it is a very interesting fish that is well worth seeking out if you are looking for something different for your tank.

This guide will teach you everything you need to know about Schwartz’s catfish care. You’ll learn about their diet, size, lifespan, and more!

Species overview

Schwartz’s catfish (scientific name: Loricariichthys schwartzi) is a type of armored catfish that is native to Brazil.

They are found in a wide range of habitats but prefer slow-moving waters with a lot of vegetation. This could be anything from a river to a swamp.

In the wild, they are omnivores and will eat just about anything they can find. This includes plants, small invertebrates, and even other fish.

In the aquarium, they are peaceful but can be a little shy. They do best in a tank with plenty of hiding spots and a moderate amount of vegetation.

Schwartz’s catfish are a popular choice for many aquarium enthusiasts because of their unique appearance. They have a brown and white striped pattern that is really quite striking.


Schwartz's catfish

Schwartz’s catfish is a fairly small and stocky fish. They have a brown or black body with a white or cream-colored belly. One of the most distinctive features of this fish is the large black spots that cover their body.

These spots are more pronounced on the juveniles and tend to fade as the fish gets older. Schwartz’s catfish also have a long barbels. The barbels on the males are usually longer than the females.

The dorsal fin of this fish is short and rounded. The anal fin is also short and rounded. They have a forked caudal fin. Schwartz’s catfish have a small mouth that is located at the bottom of the head.


Schwartz’s catfish can live for up to 20 years in captivity, although the average lifespan is 10 to 12 years. These fish are very long-lived compared to other freshwater fish.

As with all fish, the lifespan of Schwartz’s catfish can be impacted by the quality of care they receive. Poor water quality, stress, and a suboptimal diet can all shorten their lifespan.


Schwartz’s catfish can grow to be up to 4 inches long.


Tank Size

The recommended tank size for Schwartz’s catfish is a minimum of 30 gallons. This is for a single fish but, as with most fish, it’s best to keep them in a school.

If you’re looking to keep a school of Schwartz’s catfish you should consider a tank that’s at least 60 gallons. This will give them enough room to swim and explore without feeling too cramped.

Water Parameters

Schwartz’s catfish are a tropical species, so they prefer warm water with a consistent temperature. They also like slightly acidic water with a pH between 6.5 and 7.5.

Water hardness is not as critical, but they prefer soft to medium-hard water. A water hardness of 4 to 8 dGH is ideal.

As for alkalinity, Schwartz’s catfish prefer water with a dKH between 4 and 8.

What To Put In Their Tank

Schwartz’s catfish are a bit different when it comes to setting up their tank. Most of the time, when you’re setting up a freshwater aquarium, you want to include a lot of hiding places and cover.

This is not the case with Schwartz’s catfish. These fish like to be out in the open and feel secure in their environment.

This means you don’t need to go overboard with hiding places and you can use a variety of different substrates.

We recommend a sand substrate for these fish. They like to dig and a softer substrate will be more comfortable for them.

You can include some rocks and driftwood in their tank if you want, but don’t feel like you need to. These fish are more than happy to swim in open water.

As for plants, you can use anything that’s compatible with a sand substrate. Just be aware that these fish like to dig and uproot plants, so you might want to go with something that can bounce back (like Hornwort or Java Moss).

Common Diseases

There are a few diseases that you need to be on the lookout for when caring for Schwartz’s catfish.

The most common one is hole-in-the-head disease. This is caused by poor water quality and the presence of activated carbon in your tank.

This will present itself as one or two pits/holes in the skin of your catfish’s head. While it’s almost always curable (fixing your water quality and removing activated carbon is usually all you need to do), it will usually leave some scarring on your poor fish!

The other disease you need to be aware of is ich. This is obviously not a Schwartz’s catfish-specific illness, but since ich is so common it’s definitely worth mentioning here.

This will show itself as white spots on the body, fish, and gills of your fish. We won’t do a full ich treatment guide here (there are plenty of those online) but it’s something you need to take very seriously if it affects your fish.

The best way to prevent these diseases is to simply keep the tank in great shape. Not providing clean, high-quality water conditions will significantly increase the risk of your catfish getting sick.

Behavior & Temperament

Schwartz’s catfish are very peaceful fish that do well in a community tank. They are nocturnal, so they will be most active at night. During the day, they will often hide among the plants or other decorations in the tank.

Schwartz’s catfish are scavengers, so they will eat just about anything. They are especially fond of live foods, such as worms and insects.

These fish are very social creatures and do best when kept in groups. They will often swim together in schools.

Tank Mates

Schwartz’s catfish are peaceful and can get along with most species. They’re not aggressive and can get along with most fish.

Other docile fish species are best for creating a community tank. Some good Schwartz’s catfish tank mates include:

  • Platy Fish
  • Guppies
  • Cherry Barbs
  • Endler’s Live Bearers
  • Pygmy Cories
  • Swordtails
  • Snails


Schwartz’s catfish breeding is not an easy task. They are a bit difficult to sex and they require a very specific environment.

The first step for breeders is usually sexing. Unfortunately, male and female Schwartz’s catfish don’t have a ton of differences in their appearance when they’re not breeding. They look virtually identical.

The only way to sex them is by looking at their ventral fins. The male’s ventral fins are shorter and thinner than the female’s.

It’s only when they are ready to breed that females start to stand out. Schwartz’s catfish don’t reach maturity until about two years of age. When they are ready to spawn, females can balloon in size. In some cases, you may even see their ovaries through the skin.

Luckily, Schwartz’s catfish are communal breeders. You don’t have to pair them off to get results. To maximize the chances of spawning, you can keep a large group together and put them all in a specialized breeding tank.

The key to successful breeding is to make them as comfortable as possible. The best way to do that is to recreate their natural spawning grounds. Wild Schwartz’s catfish lay eggs in very shallow waters with dense vegetations.

Your breeding tank should have lower water levels and live floating plants. Some extra plants in the water may also help to promote breeding. Keep the light levels low and adjust the quality of the water. Lower the water hardness a bit and raise the pH to 6.5.

Once your tank is set up, give the fish time to acclimate and get comfortable. Then, feed them plenty of live food. If everything goes according to plan, you should start to see the females get larger. You can sometimes see the green eggs through their bellies.

When this happens, monitor your fish closely. You must act fast, as Schwartz’s catfish will feed on the eggs and any fry that hatches. Keep an eye out on those floating plants. Eggs are usually laid on the underside of the plants.

The eggs will have a very vibrant green color to them, so they shouldn’t be too hard to spot. Plus, hundreds of eggs are laid at one time. Just look for large clumps of green. Once you see them, return your adult Schwartz’s catfish back to their regular tank.

Eggs only take 24 hours to hatch. Those tiny little fish fry will feed on the Infusoria that’s on your live plants. You can supplement that meal with freshly-hatched brine shrimp or crushed-up flake food. Make sure to feed the fry regularly to increase survival rates.


Schwartz’s catfish are a great choice for beginner aquarists. They are easy to care for and are very peaceful fish. They are also very active and will often be seen swimming around the tank.

Overall, we think Schwartz’s catfish are a great choice for anyone looking for a low-maintenance fish.